The effect of heat treatment on the microstructure of spray formed AISI M2 high-speed steel is under evaluation. The objective of this work was-to optimise the heat treatments aiming further mechanical working. The M2 steel used in the present work was obtained in a spray forming plant in Brazil, built for processing billets preforms of light alloys and steels. The typical microstructure of spray formed materials, i.e., fine and equiaxial grains, allowed the optimisation of the M2 spheroidization heat treatment. The heat treatment at 1160 +/- 10 squareC for 12 hours was effective in producing microstructure and hardness suitable-for, further mechanical working.